If one
opts for some residency program in the US and completes PGY1
there, can he again try matching in a different university
with the experience in next years match?

There is no
clear answer to this. The most important thing involved is
that your program director has to be willing to let you go.
When u apply for next match, you will need letters from the
program where you are currently doing PGY1. So if your PD
understands the reasons why you want to leave their program
after 1st year and then apply again, only then will he/she
give letters. Hence, a clear answer can come only when you
join PGY1 and get to know your PD. I would not risking
asking your PD about this unless he/she is understanding and
you have a good reason to move. Remember, if he does allow
you to reapply, the chances are good that program will not
give you a PGY2 contract, and God forbid if you don't
rematch! if things turn out well, then yes the experience
helps you. Also if you plan to come on an H1,think again, as
this wastes 1 year on you H1.

Sonica

This is a
tricky question and agree to something's that Sonica
mentioned. I have done this in the past, so here are some
tips:

1. If you
want to switch PGY-1 to PGY-1, it will be very difficult;
most programs get funding for each resident, and if you
repeat a year, they lose a significant amount of money and
most programs will not do it (except the major universities,
big hospitals with large amount of money).

2. PGY-1 to
PGY-2 is ok, and acceptable and people do it all the time
and if you search hard and long enough you will find
something...it is a gamble however. Many PGY-2 spots open up
as people move all the time for various reasons such as
spouse etc.

3. You will
need a letter of recommendation from your PD before you can
apply for the switch; the new program will not even meet you
without a letter from the current PD; so forget even doing
it on the sly. The best policy is honesty and being
straightforward.

Again
nothing is set in stone and it is a gamble, people do it all
the time year after year.

Sandeep

This also
depends on which visa upi are on. If you are on H1 or J1,
your life is in your current PD's hands. If you are a green
card holder or beyond, you are your own boss. Even if you
get fired, you can always get something else. Another thing
to consider is a prelim year - get the experience, and then
reapply. That is perfectly fine and desirable if you are
thinking of getting into a better program.